A prior-art pressure switch for high pressure such as a pressure switch for CO2 device and a pressure switch for construction machine mainly includes a switch case, a pressure response member and a holder as illustrated in Patent Literatures 1 and 2. The switch case has a contact portion opened/closed along with pressure detection of the pressure response member. The pressure response member includes a pressure sensing member such as a diaphragm, a rod for transmitting movement of the pressure sensing member to the contact portion of the switch case, and a pressure sensing chamber communicating with a pressure source via a pressure guide pipe. The holder integrally connects the switch case and the pressure response member by a swaging processing, and retains them. In this type of the pressure switch, extremely high pressure-resistant performance is required particularly in retaining of the pressure response member exposed to high pressure. In order to ensure high pressure-resistant performance, an increase of a thickness of an annular side wall of the holder that retains the pressure response member has been usually employed.